Mitochondria are heterogeneous and highly dynamic organelles, playing critical roles in adenosine triphosphate (ATP) synthesis, metabolic modulation, reactive oxygen species (ROS) generation, and ...cell differentiation and death. Mitochondrial dysfunction has been recognized as a contributor in many diseases. The kidney is an organ enriched in mitochondria and with high energy demand in the human body. Recent studies have been focusing on how mitochondrial dysfunction contributes to the pathogenesis of different forms of kidney diseases, including acute kidney injury (AKI) and chronic kidney disease (CKD). AKI has been linked to an increased risk of developing CKD. AKI and CKD have a broad clinical syndrome and a substantial impact on morbidity and mortality, encompassing various etiologies and representing important challenges for global public health. Renal mitochondrial disorders are a common feature of diverse forms of AKI and CKD, which result from defects in mitochondrial structure, dynamics, and biogenesis as well as crosstalk of mitochondria with other organelles. Persistent dysregulation of mitochondrial homeostasis in AKI and CKD affects diverse cellular pathways, leading to an increase in renal microvascular loss, oxidative stress, apoptosis, and eventually renal failure. It is important to understand the cellular and molecular events that govern mitochondria functions and pathophysiology in AKI and CKD, which should facilitate the development of novel therapeutic strategies. This review provides an overview of the molecular insights of the mitochondria and the specific pathogenic mechanisms of mitochondrial dysfunction in the progression of AKI, CKD, and AKI to CKD transition. We also discuss the possible beneficial effects of mitochondrial-targeted therapeutic agents for the treatment of mitochondrial dysfunction-mediated AKI and CKD, which may translate into therapeutic options to ameliorate renal injury and delay the progression of these kidney diseases.
Multiple Object Tracking (MOT) has gained increasing attention due to its academic and commercial potential. Although different approaches have been proposed to tackle this problem, it still remains ...challenging due to factors like abrupt appearance changes and severe object occlusions. In this work, we contribute the first comprehensive and most recent review on this problem. We inspect the recent advances in various aspects and propose some interesting directions for future research. To the best of our knowledge, there has not been any extensive review on this topic in the community. We endeavor to provide a thorough review on the development of this problem in recent decades. The main contributions of this review are fourfold: 1) Key aspects in an MOT system, including formulation, categorization, key principles, evaluation of MOT are discussed; 2) Instead of enumerating individual works, we discuss existing approaches according to various aspects, in each of which methods are divided into different groups and each group is discussed in detail for the principles, advances and drawbacks; 3) We examine experiments of existing publications and summarize results on popular datasets to provide quantitative and comprehensive comparisons. By analyzing the results from different perspectives, we have verified some basic agreements in the field; and 4) We provide a discussion about issues of MOT research, as well as some interesting directions which will become potential research effort in the future.
Brushing up functional materials Ma Shuanhong; Zhang, Xiaoqin; Yu, Bo ...
NPG Asia materials,
06/2019, Volume:
11, Issue:
1
Journal Article
Peer reviewed
Open access
Surface-grafting polymer brushes (SPB), which are used in a versatile technique to easily realize surface modifications, can be commonly used to change the inherent surface physical/chemical ...properties of materials. In particular, producing functional polymer brushes with well-defined chemical configurations, densities, architectures, and thicknesses on a material surface has become increasingly important in many fields. Achieving such goals is highly dependent on the progress of novel surface-grafting strategies, which are commonly based on surface-initiated polymerization (SIP) methods. On the other hand, practical applications have been given more attention since the SPB technique enables the engineering of materials with diverse functions. This review reports some new grafting strategies for generating polymer brush layers and then systematically summarizes research advances in the application of polymer brush-modified materials in multiple fields. Correspondingly, some necessary challenges of the SPB technique are unreservedly pointed out, with consideration given to its real applications in the future. The aim of this article is to tell readers how to engineer functional materials through SPB techniques and what can be done with polymer brushes in the future.Biomaterials: Brushing up on polymersAttaching long polymer molecules to a surface by one end creates a brush-like texture that can provide lubrication and reduce friction between moving parts. Feng Zhou and colleagues from the Lanzhou Institute of Chemical Physics, CAS, review the current approaches to surface-tethering these so-called polymer brushes and the key bottlenecks and challenges that remain to be overcome in the development of this technology. They compare grafting strategies, including using the non-covalent interaction between polymer and surface, adding an intermediate functional group to enable chemical coupling, and using a technique known as surface-initiated radical polymerization. These methods enable control of the brush’s density, architecture, and thickness, meaning the properties of the surface can be tuned. Surfaces with polymer brushes have applications in synthetic biomimetic materials and tissue engineering.
Ferroptosis is a newly identified form of regulated cell death driven by iron-dependent phospholipid peroxidation and oxidative stress. Ferroptosis has distinct biological and morphology ...characteristics, such as shrunken mitochondria when compared to other known regulated cell deaths. The regulation of ferroptosis includes different molecular mechanisms and multiple cellular metabolic pathways, including glutathione/glutathione peroxidase 4(GPX4) signaling pathways, which are involved in the amino acid metabolism and the activation of GPX4; iron metabolic signaling pathways, which are involved in the regulation of iron import/export and the storage/release of intracellular iron through iron-regulatory proteins (IRPs), and lipid metabolic signaling pathways, which are involved in the metabolism of unsaturated fatty acids in cell membranes. Ferroptosis plays an essential role in the pathology of various kidneys diseases, including acute kidney injury (AKI), chronic kidney disease (CKD), autosomal dominant polycystic kidney disease (ADPKD), and renal cell carcinoma (RCC). Targeting ferroptosis with its inducers/initiators and inhibitors can modulate the progression of kidney diseases in animal models. In this review, we discuss the characteristics of ferroptosis and the ferroptosis-based mechanisms, highlighting the potential role of the main ferroptosis-associated metabolic pathways in the treatment and prevention of various kidney diseases.
In this paper, we propose a tracking algorithm based on a multi-feature joint sparse representation. The templates for the sparse representation can include pixel values, textures, and edges. In the ...multi-feature joint optimization, noise or occlusion is dealt with using a set of trivial templates. A sparse weight constraint is introduced to dynamically select the relevant templates from the full set of templates. A variance ratio measure is adopted to adaptively adjust the weights of different features. The multi-feature template set is updated adaptively. We further propose an algorithm for tracking multi-objects with occlusion handling based on the multi-feature joint sparse reconstruction. The observation model based on sparse reconstruction automatically focuses on the visible parts of an occluded object by using the information in the trivial templates. The multi-object tracking is simplified into a joint Bayesian inference. The experimental results show the superiority of our algorithm over several state-of-the-art tracking algorithms.
•We propose a hierarchical feature alignment method to learn robust features.•We improve the feature similarity along network layers with Wasserstein distance.•The method shows a robust ...generalization ability on adversarial examples.
Deep neural networks have demonstrated excellent performance in most computer vision tasks in recent years. However, they are vulnerable to adversarial perturbations generated by adversarial attacks. These human-imperceptible perturbations often lead to severe distortion in the high-dimensional intermediate feature space, which is one of the major reasons for the vulnerabilities in deep neural networks. Therefore, input images with perturbations can completely change the predictions of the networks in the decision space. To overcome this drawback, we propose to progressively align the intermediate feature representations extracted from the adversarial domain with feature representations extracted from a clean domain through domain adaptation. The difference between two feature distributions can be accurately measured via an optimal transport-based Wasserstein distance. Thus, the deep networks are forced to learn robust and domain-invariant feature representations, so that the gap between the different domains is minimized and that the networks are no longer easily fooled by diverse adversaries. Extensive evaluations are conducted on four classification benchmark datasets in white-box attack scenarios. The evaluation results demonstrate a significant performance improvement over several state-of-the-art defense methods.
Cuticular wax, the first protective layer of above ground tissues of many plant species, is a key evolutionary innovation in plants. Cuticular wax safeguards the evolution from certain green algae to ...flowering plants and the diversification of plant taxa during the eras of dry and adverse terrestrial living conditions and global climate changes. Cuticular wax plays significant roles in plant abiotic and biotic stress tolerance and has been implicated in defense mechanisms against excessive ultraviolet radiation, high temperature, bacterial and fungal pathogens, insects, high salinity, and low temperature. Drought, a major type of abiotic stress, poses huge threats to global food security and health of terrestrial ecosystem by limiting plant growth and crop productivity. The composition, biochemistry, structure, biosynthesis, and transport of plant cuticular wax have been reviewed extensively. However, the molecular and evolutionary mechanisms of cuticular wax in plants in response to drought stress are still lacking. In this review, we focus on potential mechanisms, from evolutionary, molecular, and physiological aspects, that control cuticular wax and its roles in plant drought tolerance. We also raise key research questions and propose important directions to be resolved in the future, leading to potential applications of cuticular wax for water use efficiency in agricultural and environmental sustainability.
•Use modified emergy ecological footprint method to assess sustainability of the wind farm during its whole life cycle.•Uncertainty analysis was conducted to judge the influence on the ecological ...footprint when UEVs of materials in the input data perturbed.•Provide recommendations concerning management for wind farms.
Wind power generation has always been considered as clean energy, according with national ecological civilization construction and responding to climate change. However, from the perspective of resource conservation, wind farms directly or indirectly occupy a large amount of land resources along the entire life cycle. Based on the emergy analysis, this paper estimates the ecological footprint of a wind farm in Dalian, evaluates its sustainability, and analyzes the ecological footprint of the four phases which include wind turbines production and transportation, construction, operation and maintenance, and demolition during the life cycle of the wind farm. It was concluded that the emergy carrying capacity of the wind farm was 3879.57 hm2/a, and the emergy ecological footprint was 5117.59 hm2/a. The wind farm was in an ecological deficit. Among the four phases, the ecological footprint of construction was the largest (60.93%), wind turbines production and transportation phase (33.77%) took the second, followed by operation and maintenance (4.59%) and demolition (0.71%). The main contribution of the materials was steel, followed by concrete, ecological protection investment, fiber glass, land occupation and epoxy resin. Finally, in order to illustrate the way to achieve sustainable development of the wind farm, uncertainty analysis and scenario analysis were carried out. It was found that when 62% of the recycled materials were used for wind turbines production, the wind farm realized ecological balance. Reducing the solar transformity (UEV) of steel and concrete can also decrease the ecological footprint of the wind farm.
Three‐dimensional (3D) printing of poly(dimethylsiloxane) (PDMS) is realized with a two‐state curing strategy, i.e., photocuring for additively manufacturing high‐precision architectures followed by ...thermal cross‐linking for high‐performance objects, taking Sylgard‐184 as an example. In the mixture of base and curing agent of Sylgard‐184, the photocuring ingredient methacrylated PDMS is incorporated to form hybrid inks with not only high‐efficiency UV curing ability but also moderate rheological properties for 3D printing. The inks are then used to additively manufacture high‐precision architectures by UV‐assisted direct ink writing. Various architectures such as lattices and honeycombs, channels that can be used as microfluidics, and pressure‐proof pipes with a feature size of ≈100 µm, can be readily printed. Thereafter, thermal cross‐linking at elevated temperature is conducted to obtain the 3D PDMS objects with comparable properties to Sylgard‐184. The facile, universal two‐stage approach to 3D printing of PDMS can facilitate the development of microfluidics, flexible electronics, soft robots, and so on.
A facile photo and thermal two‐stage curing three‐dimensional (3D) printing strategy is proposed to fabricate high‐precision polydimethylsiloxane (PDMS) architectures with commercial Sylgard‐184. The results exhibit excellent mechanical performances, with a tensile strength of 3.86 MPa and an elongation at break of 123%. The universal two‐stage 3D printing of PDMS presents an enormous potential of microfluids, actuators, and many others.
Glioblastoma multiforme (GBM) is the most common and malignant type of primary brain tumor in adults. Despite important advances in understanding the molecular pathogenesis and biology of this tumor ...in the past decade, the prognosis for GBM patients remains poor. GBM is characterized by aggressive biological behavior and high degrees of inter-tumor and intra-tumor heterogeneity. Increased understanding of the molecular and cellular heterogeneity of GBM may not only help more accurately define specific subgroups for precise diagnosis but also lay the groundwork for the successful implementation of targeted therapy. Herein, we systematically review the key achievements in the understanding of GBM molecular pathogenesis, mechanisms, and biomarkers in the past decade. We discuss the advances in the molecular pathology of GBM, including genetics, epigenetics, transcriptomics, and signaling pathways. We also review the molecular biomarkers that have potential clinical roles. Finally, new strategies, current challenges, and future directions for discovering new biomarkers and therapeutic targets for GBM will be discussed.
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